Improvement in fire-alarm telegraphs



UNITED STATES PATENT OEEIcE.

JOSEPH B. STEARS, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN FIRE-ALARM TELEGRAPHS.

Specification forming part of Letters Patent No. 69,039, dated Septcmberv17, 1867. i

lsection of the magnets, armature,&c., when the latter is drawn toward the detent. Fig. 3 is a longitudinal vertical section of the magnets, armature, Src., showing the position of the latter when the current of electricity is reversed. Fig. tis an elevation of theoperating-drum for directing and reversing the electric currents, with a portion broken away.

Similar lettersindicate like partsin'the 'sev- -eral figures.

My invention is designed to be applied more particularly to fire-alarm telegraphs; and the object ofthe invention is to simplifyr the operation of working electric telegraphs to effect a great reduction in the length of wire necessary for thewhole system, and thus to effect great saving in the expense of building and operating lines; furthermore, to prevent all accidental striking of the bells by foreign currents, unless said currents are passing in an opposite direction to those operating the bellmachine, and strong enough to neutralize the latter and have a surplus of power over and above the same suiciently strong to work the machine, as may happen by shocks 'of lightning or other atmospheric inuences; and, lastly, to secure greater precision and certainty of action.

My invention consists inwerking both tne bell-tower machine and the si gnal-boxes in one and the same circuit by arranging a steel varmature in such a manner that it will act upon the detent'in two diii'erent ways by twice reversing the circuit. The armature, beingpivoted in the usual way, is provided with two alims, with rests for the detent. When the armature isattracted by one or more magnets.

toward the detent andthe current is reversed, it will be repulsed andattracted by the .opposite magnets, and the lower arm-will be raised and arrest the detent. By again reversing the circuit the detent becomes released, falls, and .acts upon the towerhells by releasing the train of wheel-work. The magnets in the signalboxes, heilig simply electro-magnets, are not operated by the'reversal of the current, but are operated by breaking and closing the circuit, and will not operate the bell-machine magnets on account ot the armature being held against the first magnet by reason of its own magnetism.

Referring to the drawings, a a a a', &c., represent magnets, of which there may be one or more pairs, with a steel armature, c, pivoted ath ha, and provided with the two arms f and g, and working between the poles Ii i i 'i'. The detent, consisting of two arms at right angles, ory nearly so, is attached' to an arbor, c c, which is liournaled i-n two standards, s The magnets i vi z" are connected in such a manner that the steel armature c will be drawn toward the detent when at rest, the end of arm b being supported by the rest or catch of arm fofarmatnre. Whenthe current is reversed by the reversing-cylinder k, or otherwise, the polarity of the steel armature remaining the same, it is forced ofi by the first electro-magnet z' i', against which it rests, and is also attracted by the otheror second electro-magnet t" i', the arm f of armature will fall back, al lowing the detent to falluntil the arm b' is caught by the rest or catch of the lower arm,-

g, of the armature. When the current is again reversed the lower arm ot the dctent is fully released, allowing the weight d to fall, and thus releasing the train of wheel-work and operating the machine in the usual manner.

The reversingcylinderk is provided with annular metal rings p p q q', Svc., which are in contact with the conducting-springs m m' n n,

respectively. Thewires u u connect and carry the circuit to the rings p and qand p q... The insulated wires o lv. connect and carry the circuit to the rings p q' and p q, respectively, and in such a manner that the insulated wirev o passes through a recess in the cylinder underneath the ring q to the ring q', arid the wire fu' passes in a like ,manner to ring q. The rings q q" have two breaks on their circumference at equal distances'from the wires u fu and a e'. The positive and ,negative electric currents pees ifm-m betesynhfoagh Wes, Tee focme may he atteehei. 5e the spring mi the ete io he spying m. -The pesitve electre current 'ill mes from m to .the ring p mtt canvas to the Hemmer-Se Wire u, when it Wi be Hensmite "0- q, from heye te spring n, and :teem theuee 1:0 be-maeline md thesignedbbexee and thence beek by either a memb he 01 gmum eieu to spring we and ring q' eve1 the zeneveffse wie the spying@ spzu m', :me Sfnenee to thenegaive pee of thebebery, mus eempletieg the eire'it.

By mix-ning be eynde' one-half :L revolution the pesiti've current wl pees 'from ring p,t1eugh the iesulete. Wire 'v underneath the .ving g? to the ring g', and thence to spring n te bebmaehne and boxes, retumn g te sieg gj ewa, passing *1:0 ring'` A39", femme thmugh j m io the e/hef pele ef the baiaezy, @n eiug 'le reveujieu of the eylme, the

t* is again reversed and brought te its' new al e1: ieee cemiien. By this @Imagement hm euebe, 'ze dispense 2m indepene wife e @ironie-weigh hereto'oe maehine, and heuee sawing newly @eeh/@LT1 @ze 'amount ef wife which has neen uee in melklng {ire-alarm teegrephs, together with :Iliinedeuta expenseseontingen en hesedme, sueh es se ,airs, renewal, and ext-ra abor employed.

What claim as new, and desire to secure by Letters Patent, 'isx l. The empoyment ofreverse Gurreus fer epemtiug the bell-striking mechanism, iu the mnner ami for the purpose speeed.

2. Gleim sueeessivey engagiegeud Gisellgagingthe arms b f5 of a bent ever etmehed to the weighted shaft et' the hdi-striking mech4 @mism by the mevement of a megnezed turey which, by means of reverse currentse caused to oscillare between two destro-megnets, in the manner set forth.

4in testimony 'whereof have signed my mmxe to this speeeeten in the gru'esenee of two sesebng Witnesses.

JOSEPH. B. SEEABNS.

@Witnesses Jos. EL ADAMS, 

